Method and plant for handling a green tyre for bicycle

ABSTRACT

A green tyre ( 2 ) for bicycles is built, comprising at least one carcass ply ( 4 ) having axially opposite end flaps ( 4   a ) engaged with respective bead cores ( 5 ) and a tread band ( 6 ) applied in a radially outer position around said at least one carcass ply ( 4 ). The built tyre ( 2 ) removed from the building drum, is profiled so as to translate the tread band ( 6 ) in a radially outer direction with respect to the bead cores ( 5 ), so as to impart a cross-sectional convex profile to the tyre ( 2 ) in a radially outer direction. The profiled tyre is engaged by means of a transfer member ( 31 ) comprising a gripping device ( 30 ) which retains it at the radially outer surface ( 2   b ) so as to maintain said cross-sectional convex profile in a radially outer direction.

The present invention relates to a method and a plant for handling agreen tyre for bicycle.

The building of a tyre for bicycles usually provides that one or morecarcass plies are applied according to a cylindrical configurationaround an outer surface of a building drum. Each bead core of a pair ofbead cores is fitted or applied around one of the axially opposite endflaps of the carcass ply. The end flaps are then turned up around therespective bead cores. A tread band is then applied around the carcassply lying against the building drum, in an axially centred position withrespect to the bead cores.

The mutual axial distance between the bead cores remains unchangedduring the entire building process, including the application of thetread band. This process aspect represents a unique feature thatdistinguishes bicycle tyres from tyres for motor vehicles. For thelatter, in fact, a mutual approach step of the bead cores is normallyprovided to shape the carcass structure according to a toroidalconfiguration in the coupling step with the belt structure.

Once the building has been completed, the built green tyre for bicycleis removed from the drum to be transferred in a mould or a vulcanisationpress, where the tyre itself is subjected to a moulding andvulcanisation treatment aimed at determining the structuralstabilisation thereof via cross-linking of the elastomeric materialpresent therein, as well as optionally imprinting a desired treadpattern on the tread band.

The term “elastomeric material” is used to designate a compositioncomprising at least one elastomeric polymer and at least onereinforcement filler. Preferably, such a composition further comprisesadditives such as cross-linking agents and/or plasticisers. Due to thepresence of the cross-linking agents, such a material can becross-linked by heating so as to form the final manufactured article.

The terms “radial” and “axial” and the expressions “radiallyinner/outer” and “axially inner/outer” are used with reference to theradial direction of the tyre (i.e. to a direction perpendicular to theaxis of rotation of the tyre) and to the axial direction of the tyre(i.e. to a direction parallel to the axis of rotation of the tyre). Theterms “circumferential” and “circumferentially” are instead used withreference to the annular development of the tyre. A radial plane of thetyre contains the axis of rotation thereof.

The expressions “low”, “below”, “lower” or “inferiorly”, and “high”,“above”, “upper” or “superiorly” are used to designate a relativeposition of an element with respect to another and/or of an element withrespect to the ground.

“Geometric axis of rotation” of a green tyre means the axiscorresponding to the axis of rotation of the vulcanised tyre whenmounted in operating conditions on a respective mounting rim. The term“axial centreline plane” of the moulded and vulcanised or green tyre isused to designate a plane perpendicular to the geometric axis ofrotation and equidistant from the axially outer portions of the tyreitself.

The term “annular centreline band” is used to designate an annularportion of the green tyre divided symmetrically by the axial centrelineplane of the green tyre.

The term “gripping axis” of a gripping device is used to designate areference axis around which a gripping sector is arranged, comprising atleast one gripping area, activated on the green tyre.

The term “tyre width” is used to designate the maximum axial dimensionof the moulded and vulcanised tyre.

There essentially are at least two types of vulcanisation press forbicycle tyres, with single location and multiple location, respectively.

Single-location presses are provided with a single vulcanisation mould,normally made of two half-parts, housing a radially expandablevulcanisation membrane, fixed around a central support.

The green tyre coming from the building line is picked up by an operatorto be fitted around the vulcanisation membrane. The half-parts of themould are closed and the membrane, previously mounted inside thevulcaniser, is inflated with pressurised steam or compressed air, ornitrogen or a mixture of the previous fluids, so as to press the tyreagainst the inner walls the mould and cause the vulcanisation thereof byheat. At the end of the vulcanisation, the mould half-parts are movedaway from each other and the operator picks up the vulcanised tyre toreplace it with a new green tyre to be vulcanised. This machineconfiguration, where each mould has a relative membrane previouslymounted on the vulcaniser, can generally have up to two, three mouldsstacked on top of each other.

There are also multiple-location vulcanisation presses, includingmultiple vulcanisation moulds stacked vertically on top of each other,generally up to a maximum of 7 moulds where, however, the membrane isnot fixed on the vulcaniser. The use of multiple-location presseswithout fixed membrane or so-called central mechanism requires that anoperator provides to introduce an expandable tubular bladder within eachgreen tyre built to be treated. The operator then introduces each tyrecoupled to the respective vulcanisation bladder between the half-partsof each vulcanisation mould, making sure that each bladder is connectedto a steam feeding conduit, or compressed air, or nitrogen or a mixtureof the previous fluids, by means of valve members provided for thispurpose. At the end of the vulcanisation, the half-parts of each mouldare moved away from each other and the operator picks up the vulcanisedtyre to replace it with a new green tyre to be vulcanised and remove thevulcanisation bladder from each vulcanised tyre.

There are multiple-location presses in which the opening and closingcycles of the moulds and of vulcanisation are carried out simultaneouslyon all tyres loaded into the press. In other cases, a sequential openingof the moulds is carried out so as to perform the vulcanisation of thesingle tyres with interspersed times according to an on-going process.

The Applicant has noted that bicycle tyres, especially when green, areoften without a structural consistency sufficient to allow the properhandling thereof by means of mechanical devices.

This is because bicycle tyres are often provided with bead cores innon-metallic material, for example in composite material based onnatural or synthetic fibres (carbon, aramid, etc.) to allow the finishedtyre to be folding. Moreover, as stated above, bicycle tyres are oftendevoid of reinforcement belt layers interposed between the carcassply/plies and the tread band. In particular, the Applicant has notedthat once removed from the building drum, a green bicycle tyre tends todeform under the effect of internal stresses and of its own weight, andthis is done randomly and uncontrollably in circumferential direction,where the circular shape is lost due to the low resistance of the beadcores, and/or in the axial development direction due to the shrinkage ofthe materials or the weight of the components thereof.

For these reasons, bicycle tyres are often produced using mostly manualprocesses.

The Applicant has also felt that, in order to facilitate mechanisedhandling, it should be ensured that the green tyre can be picked upsafely and reliably and repositioned with suitable accuracy for thepurposes of subsequent processing.

The Applicant therefore deems it desirable to find a solution so thatgreen tyres for bicycle can be handled by mechanised handling,maintaining a predetermined precise positioning, despite their tendencyto take a substantially random deformed development.

The Applicant has finally found that the retention implemented at aradially outer surface of the green tyre suitably profiled according toa shape that opposes its tendency to take a substantially randomdeformed development ensures a proper handling of the green tyre both inthe handling step and in the arrangement step within a subsequentworking station, such as in a mould or vulcanisation press.

More precisely, according to a first aspect thereof, the inventionrelates to a method for handling a green tyre for bicycle.

Preferably, it is provided to arrange a green tyre for bicycle profiledaccording to a circular development around a geometric axis of rotationof the green tyre and according to a cross-sectional convex profile in aradially outer direction.

Preferably, the geometric axis of rotation is arranged in a predefinedposition.

Preferably, it is provided to arrange a gripping device defining agripping sector distributed around a gripping axis.

Preferably, said gripping sector comprises at least one gripping areathat can be activated on the green tyre.

Preferably, it is provided to align said gripping axis with thegeometric axis of rotation of the green tyre for coaxially positioningthe gripping device around the green tyre.

Preferably, it is provided to activate said at least one gripping areaagainst a radially outer surface of the green tyre so as to retain saidgreen tyre thus arranged.

Preferably, it is provided to handle said gripping device towards asubsequent working station of the green tyre while said gripping devicecontinues to retain the green tyre.

More precisely, according to a second aspect thereof, the inventionrelates to a plant for handling a green tyre for bicycle.

Preferably, a profiling unit is provided, configured for receiving agreen tyre for bicycle and for profiling it according to a circularextension around a geometric axis of rotation of the green tyre andaccording to a convex cross-sectional profile in a radially outerdirection, arranging it with said geometric axis of rotation in apredefined position with respect to the profiling unit.

Preferably, a gripping device is provided, defining a gripping sectordistributed around a gripping axis.

Preferably, said gripping sector comprises at least one gripping areathat can be activated on the green tyre.

Preferably, said gripping device is configured for retaining from theoutside said green tyre at a radially outer surface against which saidat least one gripping area activates.

Preferably, a transfer member is provided, comprising said grippingdevice and configured for handling said gripping device towards at leastone subsequent working station.

Preferably, a centring group is provided, configured for aligning saidgripping axis with the geometric axis of rotation of the green tyrearranged in the profiling unit.

The Applicant believes that retaining the tyre from the outside allowsthe automated handling thereof by the transfer member, thus overcomingthe problems described above related to the operator's safety. Thecentring of the gripping device with respect to the green tyre and theactivation of the gripping area at the radially outer surface of thetyre further allow accurately engaging the tyre itself, thus overcomingthe problems related to the springback effect of the materials andensuring the correct positioning for further processing, for example inthe vulcanisation mould.

The present invention, in at least one of the above aspects thereof, canexhibit at least one of the following preferred features.

Preferably, said gripping sector comprises a plurality of said grippingareas distributed discretely around said gripping axis.

The Applicant believes that the use of a plurality of gripping areasdiscretely distributed around the gripping axis allows a uniform grip ofthe green tyre.

Preferably, each gripping area is defined by a substantially circulararea.

Preferably, the gripping areas are circumferentially distributed aroundthe gripping axis along a same gripping circumference.

Preferably, said gripping sector comprises a single gripping areadistributed continuously around said gripping axis.

The Applicant believes that the use of a single gripping area allows ahigh precision in the relative positioning without introducing excessivestructural and/or operating complications.

Preferably, said gripping sector is arranged circumferentially aroundsaid gripping axis and defines an annular gripping portion.

The Applicant believes that by operating by means of an annular grippingportion it is possible to improve the relative positioning accuracybetween the gripping device and the green tyre and the respectivecentring thereof.

Preferably, said annular gripping portion is defined by a plurality ofgripping areas circumferentially distributed around the gripping axisalong a same gripping circumference.

Preferably, it is provided to select an annular gripping band of thegreen tyre arranged around the geometric axis of rotation at apredetermined height along the geometric axis of rotation itself andactivate said at least one gripping area of the annular gripping portionagainst the radially outer surface of the annular gripping band.

The achievement of a precise positioning of the tyre also along an axialdirection is thus facilitated.

Preferably, the annular gripping portion is brought to a radially outerposition with respect to the annular gripping band and arranged at theheight of the annular gripping band.

Preferably, the annular gripping portion is brought to a radially outerposition with respect to the annular gripping band with said grippingcircumference aligned with an axial centreline plane of the green tyre.

Preferably, it is provided to adjust the annular gripping portion to anadjustment diameter larger than the outer diameter of the annulargripping band, corresponding to a rest configuration, before bringing itto a radially outer position with respect to the annular gripping band.

Preferably, it is provided to carry out a relative axial translationmovement between said annular gripping portion and said annular grippingband to arrange them at the same height along the geometric axis ofrotation of the green tyre.

Preferably, it is provided to adjust the annular gripping portion to agripping diameter smaller than the adjustment diameter, corresponding toa working configuration.

Preferably, said gripping diameter coincides with the outer diameter ofthe annular gripping band so as to activate said annular grippingportion against the annular gripping band.

Preferably, the adjustment of the annular gripping portion is carriedout by adjusting simultaneously and synchronously the radial position ofeach gripping area.

Preferably, the adjustment of the annular gripping portion is carriedout by adjusting autonomously the radial position of each gripping area.

Preferably, said annular gripping band and the relative height along thegeometric axis of rotation of the green tyre are selected as a functionof the tyre width.

The Applicant believes that the selection carried out as a function ofthe tyre width ensures the best result in terms of centring andretention of the profiling of the green tyre.

Preferably, said annular gripping band is an annular axial centrelineband of the tyre.

Preferably, said annular gripping band belongs to a tread band of thetyre.

The Applicant believes that the selection of an annular axial centrelineband or of the tread band improves the gripping and the holding of thegreen tyre from the outside.

Preferably, activating said gripping area against the radially outersurface of the green tyre comprises arranging said annular grippingportion in contact with said annular gripping band.

Preferably, during the handling of the gripping device, the green tyreis retained by the gripping device hanging only at the annular grippingband.

Preferably, handling said gripping device comprises centring thegripping device with said subsequent working station by aligning saidgripping axis with a reference axis of the subsequent working station.

Preferably, it is provided to carry out a relative axial translationmovement between said gripping device and said subsequent workingstation for bringing said annular gripping band at an axial referencearranged at a predetermined height along the reference axis of thesubsequent working station.

Preferably, it is provided to release said green tyre in said subsequentworking station.

Preferably, said gripping device comprises a plurality of grippingelements distributed around the gripping axis, each gripping element ofsaid plurality of gripping elements defining a gripping area.

Preferably, it is provided to adjust the gripping elements by radiallyhandling them with respect to the gripping axis of the gripping devicefor activating or deactivating said gripping areas against the radiallyouter surface of the green tyre.

Preferably, it is provided to adjust the gripping elements by arrangingthem in a radial adjustment position arranged with respect to thegeometric axis of rotation at an adjustment distance larger than theradius of the radially outer surface of the green tyre to be retained,corresponding to a rest configuration.

Preferably, it is provided to adjust the gripping elements by handlingthem from the adjustment distance to a gripping distance, smaller thanthe adjustment distance, corresponding to a working configuration.

Preferably, said gripping distance coincides with the radius of theradially outer surface of the green tyre so as to activate said grippingelements against the radially outer surface of the green tyre.

Preferably, the adjustment of the gripping elements is carried out byadjusting simultaneously and synchronously the radial position of allgripping elements.

Preferably, the adjustment of the gripping elements is carried out byadjusting autonomously the radial position of each gripping element.

Preferably, activating said gripping areas against the radially outersurface of the green tyre comprises exerting a pneumatic suction actionthrough said gripping elements adapted to generate a predetermineddegree of vacuum between the radially outer surface of the green tyreand the gripping areas.

Preferably, arranging said green tyre comprises exerting a thrust actionon a radially inner surface of the green tyre directed radially outwardsfor expanding said green tyre from the interior up to reaching anexpanded configuration.

The thrust action generates a profiling carried out from the interior ofthe tyre which facilitates access to the radially outer surfaces thereoffor the purposes of subsequent handling.

Preferably, said at least one gripping area is activated against theradially outer surface of the green tyre arranged in the expandedconfiguration.

Preferably, it is provided to cancel said thrust action before handlingsaid gripping device.

Preferably, the gripping elements are adjusted to the gripping distancecorresponding to the outer radius of the green tyre in the expandedconfiguration.

Preferably, the annular gripping portion is adjusted to the grippingdiameter corresponding to the outer diameter of said annular grippingband in the expanded configuration.

Preferably, during the handling towards the subsequent processingstation, said gripping device holds the green tyre from the outside andkeeps said annular gripping band in the expanded configuration.

Preferably, activating said at least one gripping area against theradially outer surface of the green tyre comprises arranging said atleast one gripping area in contact with said radially outer surface ofthe green tyre.

Preferably, said gripping area is activated against the radially outersurface of the green tyre by means of an attraction action acting on theradially outer surface of the green tyre moving away from the geometricaxis of rotation.

Preferably, said attraction action is exerted by means of a pneumaticsuction action adapted to generate a predetermined degree of vacuumbetween the radially outer surface of the green tyre and said at leastone gripping area.

Preferably, the pneumatic suction action is activated when the radiallyouter surface and said at least one gripping area are in mutual contact.

Preferably, prior to handling said gripping device, it is provided toverify the attainment of a predetermined degree of vacuum between theradially outer surface of the green tyre and said at least one grippingarea, said predetermined degree of vacuum being indicative of the actualgripping of the green tyre.

Preferably, handling said gripping device comprises centring thegripping device with said subsequent working station by aligning saidgripping axis with a reference axis of said subsequent working station.

Preferably, it is provided to release said green tyre in a suitableprocessing position with respect to the subsequent working station.

Preferably, said at least one gripping area is activated against aradially outer surface of the green tyre comprising an axial centrelineplane of the green tyre.

Preferably, said at least one gripping area is activated against aradially outer surface of a tread band of the green tyre.

Preferably, during the handling of the gripping device, the green tyreis retained by the gripping device hanging only at the radially outersurface of the tread band.

Preferably, said green tyre is maintained with said geometric axis ofrotation arranged transversely with respect to a horizontal geometricplane. Even more preferably, said green tyre is maintained with saidgeometric axis of rotation arranged vertically.

Preferably, said gripping device is handled with said gripping axisarranged transversely with respect to a horizontal geometric plane. Evenmore preferably, said gripping device is handled with said gripping axisarranged vertically.

Preferably, said green tyre is arranged and positioned in the subsequentworking station defining a reference axis arranged transversely withrespect to a horizontal geometric plane. Even more preferably, saidgreen tyre is arranged and positioned in the subsequent working stationdefining a reference axis arranged vertically.

Preferably, handling said gripping device comprises loading said greentyre in a vulcanisation mould.

Preferably, said gripping elements are circumferentially distributed sothat said gripping areas define an annular gripping portion.

Preferably, said adjustment apparatus comprises at least one drivingactuator configured for adjusting the radial position of said grippingelements up to reaching a radial adjustment position arranged withrespect to the geometric axis of rotation of the green tyre at anadjustment distance larger than the radius of the radially outer surfaceof the green tyre to be retained, corresponding to a rest configuration.

Preferably, said at least one driving actuator is configured foradjusting the radial position of said gripping elements up to reaching aradial gripping position arranged with respect to the geometric axis ofrotation of the green tyre at a gripping distance smaller than theadjustment distance, corresponding to a working configuration.

Preferably, said driving actuator is configured for adjustingsimultaneously and synchronously the radial position of the grippingelements.

Preferably, a plurality of actuators is provided, configured forautonomously adjusting the radial position of each gripping element orgroups of gripping elements.

Preferably, said gripping elements are arranged in groups and each groupis associated with a driving actuator configured for adjusting theradial position thereof.

Preferably, said gripping elements are configured for exerting apneumatic suction action adapted to generate a predetermined degree ofvacuum between the radially outer surface of the green tyre and thegripping areas.

Preferably, each gripping element comprises a suction or spongyinterface adapted to come into contact with the radially outer surfaceof the green tyre. Preferably, said interface is connected to a suctiondevice.

Preferably, a detection device is provided for detecting the degree ofvacuum between the radially outer surface of the green tyre and saidgripping areas applied by the gripping elements.

Preferably, the detection device is configured for generating adetection signal indicative of the detected degree of vacuum.

Preferably, a control unit is provided, programmed for receiving saiddetection signal and comparing it with a threshold value indicative ofthe actual grip of the green tyre.

Preferably, the control unit is programmed for activating said transfermember if said comparison confirms the actual gripping of the greentyre.

Preferably, said gripping device is a loader of a vulcanisation mould.

Preferably, said centring unit comprises a first centring portionassociated with the gripping device and a second centring portionassociated with the profiling unit. Preferably, said first and secondcentring portions define a shape coupling configured for aligning saidgripping axis with the geometric axis of rotation of the green tyrearranged in the profiling unit.

Preferably, said gripping device comprises a frame supporting saidgripping sector.

Preferably, said frame is movable along the gripping axis with respectto the first centring portion.

Preferably, at least one elastic element is interposed between the frameand the first centring portion. Even more preferably, the elasticelement is configured and arranged so as to oppose the approach betweenthe frame and the first centring portion and allow the elastic return toa predetermined relative position of the frame and of the first centringportion.

Preferably, said profiling unit is configured for receiving said greentyre for bicycle with said geometric axis of rotation arrangedtransversely with respect to a horizontal geometric plane. Even morepreferably, said profiling unit is configured for receiving said greentyre for bicycle with said geometric axis of rotation arrangedvertically.

Preferably, said profiling unit is configured for exerting a thrustaction directed radially outwards on a radially inner surface of thegreen tyre for expanding said green tyre from the interior up toreaching an expanded configuration.

The profiling action carried out from the interior of the tyrefacilitates access to the radially outer surfaces thereof for thepurposes of gripping and handling.

Preferably, said profiling unit comprises a centring mandrel having acentral geometric axis and a radially expandable profiling memberextending circumferentially around said central geometric axis.

Preferably, said profiling member comprises an expandable membrane fixedaround an outer circumferential surface of the centring mandrel.

Preferably, said profiling member comprises a plurality of sectorsradially movable with respect to said central geometric axis.

Preferably, said central geometric axis is arranged transversely withrespect to a horizontal geometric plane. Even more preferably, saidcentral geometric axis is arranged vertically.

Preferably, said gripping device is configured for retaining said greentyre hanging with said geometric axis of rotation and said gripping axisarranged transversely with respect to a horizontal geometric plane. Evenmore preferably, said gripping device is configured for retaining saidgreen tyre hanging with said geometric axis of rotation and saidgripping axis arranged vertically.

Preferably, said plant is configured for maintaining said geometric axisof rotation of the green tyre arranged transversely with respect to ahorizontal geometric plane. Even more preferably, said plant isconfigured for maintaining said geometric axis of rotation of the greentyre arranged vertically.

Preferably, an adjustment apparatus is provided, configured forarranging said at least one gripping area in predetermined radialpositions with respect to the geometric axis of rotation of the greentyre.

Further features and advantages will become more apparent from thedetailed description of a preferred but non-exclusive embodiment of amethod and a plant for handling green tyres for bicycle according to thepresent invention. Such a description is given hereinafter withreference to the accompanying drawings, provided only for illustrativeand, therefore, non-limiting purposes, in which:

FIGS. 1 to 4 schematically show cross-sectional views of some operatingsteps designed to build a green tyre for bicycle;

FIG. 5 shows a perspective bottom view of a plant for handling a greentyre for bicycle according to the invention;

FIG. 6 schematically shows a perspective top view of a profiling unitforming part of the plant according to the present invention;

FIG. 7 schematically shows a cross-sectional view of the profiling unitwith a green tyre fitted around a profiling member in contractedcondition;

FIG. 8 schematically shows a cross-sectional view of the profiling unitin FIG. 7 during a profiling operation of the green tyre;

FIG. 9 shows a detail in FIG. 7 during the introduction of a grippingdevice of the green tyre;

FIG. 10 shows the detail in FIG. 8 during the engagement of the greentyre with the gripping device;

FIG. 11 shows the green tyre engaged with the gripping device andremoved from the profiling unit;

FIG. 12 schematically shows a radial section view of a finished tyre forbicycle;

FIG. 13 schematically shows a perspective top view of the grippingdevice forming part of the plant according to the present inventionwhich retains a green tyre;

FIG. 14 schematically shows a side view of the gripping device in FIG.13;

FIG. 15 schematically shows a cross-sectional view of the grippingdevice in FIG. 13;

FIGS. 16-18 schematically show the gripping device that releases thegreen tyre to a central body of a vulcanisation mould.

A plant for handling a green tyre for bicycle according to the presentinvention is globally designated with reference numeral 1.

The present invention is designed for processing tyres 2 for bicycle, ofthe type schematically exemplified in FIG. 12, for example for use onroad, track, mountain bikes, e-bikes, etc.

A radially inner surface 2 a, substantially facing towards a geometricaxis of rotation “X” of tyre 2, and a radially outer surface 2 bsubstantially facing away from the geometric axis of rotation “X”, canbe identified in tyre 2.

Plant 1 is configured for maintaining the geometric axis of rotation “X”of the green tyre arranged transversely with respect to a horizontalgeometric plane “O”, preferably vertically.

Tyre 1 for bicycle has a carcass structure 3 comprising at least onecarcass ply 4 having mutually parallel cords embedded in an elastomericmatrix.

Axially opposite end flaps 4 a of the carcass ply or plies 4 are engagedto respective bead cores 5, that is, annular anchoring structuresintegrated in the regions usually identified by the name of “beads” atwhich the mechanical engagement between tyre 2 in use conditions and arespective mounting rim takes place.

A tread band 6, made of elastomeric material, is applied in a radiallyouter position with respect to the carcass structure 3.

Preferably, at least two layers of cords having a cross pattern,respectively, can be identified in the carcass structure 3. The cordsbelonging to each layer have an inclined development according to apredetermined angle, approximately between about 35° and about 65° withrespect to a circumferential development direction of tyre 2. Forexample, the presence of two carcass plies 4 may be provided, radiallysuperimposed on top of each other, each with the respective cordsextending along an inclined direction with respect to thecircumferential development of tyre 2 and according to an inclinedorientation with respect to the cords belonging to the other carcass ply4. Alternatively, as shown in FIG. 12, a single carcass ply 4 may beprovided, the end flaps 4 a whereof, turned up around bead cores 5,extend at least up to an axial centreline plane “M” of tyre 2, so as todefine each a further radially outer layer of cords having crossedorientation with respect to the cords present in the radially innerlayer.

Unlike the tyres typically designed to be used on motor vehicles, tyre 2for bicycle is generally devoid of a belt structure, that is, ofreinforcement belt layers radially interposed between the carcassstructure 3 and the tread band 6. In tyres for motor vehicles, thesebelt layers contribute to increasing the structural strength of tyre 2and to stabilising the geometry thereof, especially in the crown region,i.e. in the radially outer regions closer to the tread band 6.

In tyre 2 for bicycle, however, at least one circumferential protectivelayer 7 may be provided, interposed between the tread band 6 and thecarcass structure 3. Where present, said at least one circumferentialprotective layer 7, the task whereof is essentially to protect tyre 2from puncture, may have a textile structure or be made in the form ofcontinuous layered tape of synthetic material, and preferably has athickness not larger than 0.5 mm, preferably not smaller than 0.2 mm.Unlike a real belt structure, the circumferential protective layer orlayers optionally present in tyre 2 for bicycle do not significantlyinfluence the structural strength, geometric stability and/or dynamicbehaviour of tyre 2 itself.

Preferably, on the radially outer surface 2 b of tyre 2 for bicycle,portions of carcass ply 4 directly exposed towards the externalenvironment can be identified between the axially outer edges of thetread band 6 and the bead cores 5. Tyre 2 for bicycle is in facttypically not provided with sidewalls, i.e. layers of elastomericmaterial applied laterally outside the carcass structure 3, eachextending between one of the beads and the respective axially outer edgeof the tread band.

In tyre 2 for bicycle, thickness “S” of the bead core 5 corresponds to ahalf of the difference between an outer circumferential diameter “De”and the seating diameter “Dc” of bead core 5 itself.

As schematised in FIGS. 1 to 4, the building of tyre 2 for bicycle infact provides that, using suitable application devices (not shown)forming part of a building unit, the carcass ply or plies 4 aredeposited according to a cylindrical configuration, such as by wrappingaround an outer surface of a building drum 9.

By means of bead core application devices (not shown), a pair of beadcores 5, for example made of composite material based on natural orsynthetic fibres and/or more seldom, metallic material, is applied at afixed mutual axial distance “D”, each around one of the axially oppositeend flaps 4 a of the carcass ply 4.

In particular, in the example shown, it is provided that each bead core5, previously made in the form of finished component, is first fittedaround the carcass ply or plies 4 in an axial position corresponding toa circumferential recess 10 formed on the building drum 9 A slightradial expansion of the building drum 9, for example by lever mechanismsforming part of said bead core application devices, causes theapplication of the bead cores 5 against the carcass ply or plies 4, eachat the respective circumferential recess 10.

Alternatively, the bead core application devices may be configured tomake each bead core 5 directly on the building drum 9, wrapping one ormore continuous cords around the carcass ply or plies 4 according to aplurality of coils axially juxtaposed and/or radially superimposed oneach other.

Turning up devices (not shown) operating at the building drum 9 thenturn up the end flaps 4 a of the carcass plies 4 around the respectivebead cores 5. During the turning up, the end flaps 4 a may be at leastpartially superimposed on each other and optionally joined in mutualdirect contact.

Tread band application devices (not shown) aid the application of atread band 6 around the carcass ply 4, in an axially centred positionwith respect to the bead cores 5. The tread band 6 may be applied inradial superimposition with respect to the turned up end flaps 4 a. Oncethe application has been completed, the turned up end flaps 4 a maytherefore be partly arranged in an axially inner position with respectto axially opposite edges of the tread band.

On occurrence, the application of the tread band 6 may be preceded bythe application of said at least one circumferential protective layer 7.

During the application of the tread band 6, an axially central portionof said at least one carcass ply 4, extending axially through an axialcentreline plane “M” equidistant from the bead cores 5, lies against thebuilding drum 9 (FIG. 4).

The tread band 6 is preferably applied maintaining the mutual axialdistance “D” of the bead cores 5 virtually unchanged. More inparticular, the mutual axial distance “D” between the bead cores 5preferably remains unchanged during the entire building process,including the application of the tread band 6.

Once the building has been completed, the green tyre 2 is removed fromthe building drum 9 to be subjected to other process steps, for exampleto be transferred to a vulcanisation press or mould.

To this end, the building drum 9 is radially axially contracted so as tofacilitate the removal of the built tyre 2. Being devoid of beltstructure and having generally bead cores 5 made from natural orsynthetic fibres (carbon, aramid, etc.), tyre 2 for bicycle tends todeform spontaneously or very easily, for example under the effect of itsown weight, as soon as it is removed from the building drum 9. In otherwords, upon removal from the building drum 9, tyre 2 loses its shapewith circular development, taking a deformed development in a random anduncontrolled manner.

Moreover, any residual elastic tensions resulting for example from theradial expansion imposed during the application of the bead cores 5induce the carcass ply or plies 4 to resume their original diameter,especially at the axially central portion. As a result, tyre 2 initiallybuilt according to a cylindrical shape, tends to take a cross-sectionalprofile substantially convex towards a radially inner direction.

The present invention aims to allow a reliable handling of the builttyre 2 for bicycle, for the transfer thereof to a vulcanisation press ormould other working station 100 subsequent to said building unit.

To this end, a profiling unit 11 is provided, comprising a centringmandrel 12 having a central geometric axis “Y”, preferably orientedtransversely to a horizontal plane “O”, for example according to avertical direction, i.e. perpendicular thereto. The centring mandrel 12comprises a support structure 13 supporting a central upright 14 towhich a support plate 15 is fixed, preferably circular in shape, havinga peripheral edge extending concentrically on the central geometric axis“Y”. A coupling shank 16 tubular in shape, having a truncated-cone upperend, is preferably fixed on an upper surface of the support plate 15,concentrically to the central geometric axis “Y”.

The centring mandrel 12 is operatively coupled to a radially expandableprofiling member 17, extending circumferentially around the centralgeometric axis “Y” and preferably arranged peripherally on the uppersurface of the support plate 15. Preferably, the profiling member 17comprises an expandable membrane 18 extending around the centralgeometric axis “Y”. The expandable membrane 18 is preferably fixedaround a support collar 19 fixed to the support plate 15 concentricallyto the central geometric axis “Y”. The expandable membrane 18 is adaptedto be inflated through the controlled introduction of air or otheroperating fluid under pressure through one or more passages formed, forexample, through the support collar 19, to radially expand away from thecentral geometric axis “Y”.

In a possible alternative embodiment not shown, the profiling member 17may optionally comprise, in addition to or in replacement of theexpandable collar 18 and the support collar 19, a plurality of sectorsradially movable with respect to said central geometric axis “Y”.

The profiling unit 11 is adapted to operatively engage the built greentyre 2, which can be fitted around the profiling member 17, for exampleby manual intervention of an operator.

The profiling unit 11 is further preferably provided with axialpositioning devices 20 of the green tyre 2 along the central geometricaxis “Y” of the centring mandrel 12.

Such axial positioning devices 20 may for example comprise acircumferential support 21 having at least one circumferentialsupporting surface 21 a concentric to the central geometric axis “Y” andprotruding in a radially outer direction with respect to said profilingmember 17, for supporting tyre 2 in supporting relation at an axiallyouter edge thereof, for example defined by one of the beads arrangedinferiorly.

The circumferential support 21 and the centring mandrel 12 are mutuallypositionable along a direction parallel to the central geometric axis“Y”, so as to facilitate the adaptation of the profiling unit 11 to theprocessing of tyres 2 having respectively different widths.

To this end, it may for example be provided that the circumferentialsupporting surface 21 a of the circumferential support 21 is defined bya plurality of elastically movable sheets peripherally borne by asupport ring 23 so as to be circumferentially distributed around thecentral geometric axis “Y”. Each sheet 22 may for example comprise anattachment portion 22 a fixed to the support ring 23 and extending awayfrom the latter parallel to the central geometric axis “Y”, and asupporting portion 22 b extending transversely from one end of theattachment portion 22 a, in a spaced apart position with respect to thesupport ring 23.

Preferably, the support ring 23 engages the centring mandrel 12 slidablyalong a direction parallel to the central geometric axis “Y”. To thisend, the circumferential support 21 may be provided with one or morerunners 24, for example borne by a radial structure 25 integral with thesupport ring 23. Runners 24 are operatively engaged along respectiveguide rods 26 protruding inferiorly from the support plate 15 of thecentring mandrel 12. An interchangeable calibrated insert 27, removablyengaged between the radial structure 25 and an abutment 28 inferiorlyborne by the support plate 15, stops the descent of the centring mandrel12 at a predetermined height with respect to the circumferential support21. The availability of a plurality of calibrated inserts 27 may beprovided, having different dimensions and selectively usable as afunction of the axial dimension of the green tyre 2 being processed.

The presence of the correct calibrated insert 27, pre-selected as afunction of the axial dimension of the tyres being processed, makes thegreen tyre 2 fitted around the centring mandrel 12, coming into contactwith the circumferential supporting surface 21 a, arrange itself withrespect to the profiling member 17 in a predetermined axial positionalong the central geometric axis “Y”. More precisely, the green tyre 2is stopped and supported in a position such that the axial centrelineplane “M” thereof coincides with an axial centreline plane “M” of theexpandable membrane 18, or other type of profiling member 17.

Preferably, sheets 22 are spaced apart from the central geometric axis“Y” by a greater extent than a maximum radius of the profiling member 17with respect to the central geometric axis “Y” itself, at least in theradially contracted condition. It is therefore possible to preventmechanical interference between sheets 22 and the profiling member 17,during a mutual axial handling thereof.

The profiling member 17 is adapted to be activated, for example byintroducing operating fluid in the expandable membrane 18, when thegreen tyre 2, previously fitted around the profiling member 17, issupported by the circumferential supporting surface 21 a.

To this end, it may be provided that the activation control of theprofiling member 17 takes place by a control unit “C” (not shown), uponreceipt of an enabling signal emitted by sensor members 29 designed todetect the presence of tyre 2 around the profiling member 17 itself.Such sensor members 29 may for example comprise an optical detectororiented towards the profiling member 17. The optical detector isconfigured to emit a presence signal when tyre 2 is interposed betweenthe profiling member 17 and the optical detector itself.

The expandable membrane 18 or other profiling member 17 is consequentlyexpanded from a radially contracted condition (FIG. 7) to a radiallyexpanded condition (FIG. 10). Preferably, in the contracted condition,the profiling member 17 has a maximum diameter smaller than the seatingdiameter “Dc”, so as to have at least one portion distant from theradially inner surface 2 a of the built tyre 2. In the expandedcondition, the profiling member preferably has, at least in the vicinityof the axial centreline plane “M”, a maximum diameter greater than theseating diameter, so as to operate against the radially inner surface 2a of tyre 2, exerting a thrust action in a substantially radialdirection from the inside towards the outside (centrifugal) to expandthe green tyre from the interior up to reaching an expandedconfiguration.

On the effect of such a thrust action, the green tyre 2 is thereforesubjected to a restoration of the development so as to take again acircular configuration around the geometric axis of rotation “X”. At thesame time, tyre 2 is centred with the geometric axis of rotation “X”thereof coincident with the central geometric axis “Y” of the centringmandrel 17 and of the profiling member 17.

The expansion of the expandable membrane 18, moreover, tends totranslate the tread band 6 towards a radially outer direction withrespect to the bead cores 5, so as to impart a cross-sectional convexprofile to the green tyre 2 towards a radially outer direction.

In order to facilitate the profiling of tyre 2 in the manner describedabove, the initial contact between the expandable membrane 18 and thebuilt tyre 2 preferably takes place in the vicinity of the axialcentreline plane “M” of tyre 2 itself.

Since the green tyre 2 positioned around the profiling member may have asignificantly deformed configuration, it is preferable that theprofiling of tyre 2 itself is not carried out by a single expansionaction, but by two or more expansion actions cyclically repeated andalternating with respective contraction actions. It may further beprovided that such cyclically repeated expansion actions follow oneanother respectively with progressively increasing intensity.

More in particular, a first expansion action may be carried out byimposing a relatively small expansion to the profiling member 17 withrespect to that imposed during a subsequent expansion action. In theexample shown, to this end it may be provided that the first expansionaction is carried out by feeding operating fluid in the expandablemembrane 18 at a first pressure value, suitable for determining asufficient circumferential stretching of tyre 2. In particular, the tyremay thus be stretched according to a circular configuration coaxially tothe central geometric axis “Y”. For example, the first expansion actionmay be carried out by feeding the operating fluid at a pressure ofbetween about 10 KPa and about 150 KPa, for a time indicatively ofbetween about 1 s and about 25 s. As a result of the first expansionaction, the profiling member 17 is preferably brought to a semi-expandedcondition, intermediate between the contracted condition and theexpanded condition (FIG. 8).

The operating fluid is then discharged from the expandable membrane 18to determine a first contraction, so as to obtain the detachment,preferably complete, from the inner surface of tyre 2.

Immediately after the contraction, indicatively within a time notexceeding about 30 s, operating fluid is again introduced in theexpandable membrane 18 at a higher pressure than the first value, so asto determine a second expansion action and subsequent profiling of tyre2. For example, the second expansion action may be carried out byfeeding the operating fluid at a pressure of between about 10 KPa andabout 150 KPa, for a time indicatively of between about 1 s and about 25s. As a result of the second expansion action, the profiling member 17can be brought to the expanded condition.

Since the green tyre 2 is already pre-profiled due to the firstexpansion action, the action of the expandable membrane 18 during thesecond expansion action may be more uniform, so as to facilitate theprofiling of tyre 2 without causing distortions due to localisedstresses.

On occurrence, more than two expansion action interspersed withrespective contraction actions may be provided.

In use, the profiling unit 11 allows receiving and arranging a greentyre 2 for bicycle profiled according to a circular development around ageometric axis of rotation “X” thereof and according to across-sectional convex profile in a radially outer direction. Thegeometric axis of rotation “X” is therefore arranged in a predefinedposition with respect to the profiling unit 11. Preferably, theprofiling unit 11 is configured for receiving the green tyre for bicyclewith the geometric axis of rotation “X” arranged transversely withrespect to a horizontal geometric plane “O”, even more preferablyvertically. After or concurrently with the execution of the profilingaction, the green tyre 2 is adapted to be engaged by a gripping device30 borne by a transfer member 31. The transfer element 31 provides toremove the green tyre from the profiling unit 11 and is configured forhandling the gripping device 30 towards at least a subsequent workingstation, such as a vulcanisation press, while the gripping device 30continues to retain the green tyre.

Preferably, the transfer member 31, for example comprising a roboticarm, preferably of the anthropomorphic type with at least 6 axes, orother handling unit, is configured to engage the green tyre 2 by thegripping device 30, while tyre 2 itself is mechanically retained so asto maintain said cross-sectional convex profile in a radially outerdirection.

The gripping device 30 defines a gripping sector 32 distributed around agripping axis “Z” and comprising at least one gripping area 33 which canbe activated on the green tyre. When the gripping device 30 retains thegreen tyre 2, the gripping axis “Z” coincides with the geometric axis ofrotation “X”, therefore, in this situation, reference will be madewithout distinction to the one or the other in the continuation of thepresent description.

According to a possible embodiment, of which the accompanying drawingsare a non-limiting example, the gripping sector 32 comprises a pluralityof gripping areas 33 distributed discretely around the gripping axis.Preferably, each gripping area 33 is defined by a substantially circulararea. Preferably, the gripping areas are circumferentially distributedaround the gripping axis “Z” along a same gripping circumference 34.

According to an alternative embodiment, the gripping sector 32 maycomprise a single gripping area distributed circumferentially around thegripping axis.

In particular, the gripping area 33 is activated against a radiallyouter surface of the green tyre 2 so as to retain it. In particular, theactivation of the gripping area 33 generates an attraction action “A”acting on the radially outer surface of the green tyre moving away fromthe geometric axis of rotation “X”. In the case of a plurality ofgripping areas 33, the activation thereof generates a plurality ofattraction actions “A” distributed around the geometric axis of rotation“X”.

Such attraction action(s) is/are exerted by means of a pneumatic suctionaction adapted to generate a predetermined degree of vacuum between theradially outer surface of the green tyre and the respective grippingarea.

Preferably, the gripping sector 32 is arranged circumferentially aroundthe gripping axis “Z” and defines an annular gripping portion. In otherwords, with reference to the embodiment shown in the accompanyingdrawings in which a plurality of gripping areas 33 is provided,distributed discretely circumferentially around the geometric axis ofrotation “X”, the gripping sector 32 corresponds to the region of thegripping device 30 intended to interact with the green tyre and formedby a sequence of gripping areas 33.

Preferably, the gripping device 30 is configured for retaining the greentyre hanging with the geometric axis of rotation “X” thereof and thegripping axis “Z” arranged transversely with respect to a horizontalgeometric plane “O”, preferably vertical. The gripping device 30preferably comprises gripping elements 35 distributed around thegripping axis “Z” and defining each a gripping area 33 of tyre 2.Preferably, the gripping elements 35 are circumferentially distributedso that the gripping areas 33 define the annular gripping portion.

An adjustment apparatus 36 is configured for arranging each grippingarea 33 in predetermined radial positions with respect to the grippingaxis “Z” and thus with respect to the geometric axis of rotation “X” ofthe green tyre. Preferably, the adjustment apparatus comprises at leastone driving actuator 37. On the action of the driving actuator 37, thegripping elements 35 and thus the gripping areas 33 are radially movablewith respect to the gripping axis “Z”, between a rest condition, inwhich they are radially distanced with respect to the gripping axis “Z”(FIG. 9), and a working condition in which they are radially approachedwith respect to the gripping axis “Z” (FIGS. 10 and 11).

Preferably, the driving actuator 37 is configured for adjusting theradial position of the gripping elements 35 up to reaching a restconfiguration corresponding to a radial adjustment position arrangedwith respect to the geometric axis of rotation “X” of the green tyre atan adjustment distance larger than the radius of the radially outersurface of the green tyre to be retained.

Moreover, the driving actuator 37 is configured for adjusting the radialposition of the gripping elements 35 up to reaching a workingconfiguration corresponding to a radial gripping position arranged withrespect to the geometric axis of rotation “X” of the green tyre at agripping distance smaller than the adjustment distance.

In the case of the annular gripping portion, the driving actuator 37 isconfigured for adjusting the annular gripping portion to an adjustmentdiameter larger than the outer diameter of an annular gripping band ofthe green tyre, corresponding to the rest configuration, andsubsequently to a gripping diameter, smaller than the adjustmentdiameter, corresponding to the working configuration.

It may be provided that a single driving actuator 37 operatessimultaneously on multiple gripping elements 35, preferably all, forexample through a handling mechanism 38 configured to radially move themin a simultaneous and synchronised manner. Each gripping element 35 mayfor example comprise a support 39, such as plate-shaped and extendingparallel to the gripping axis “Z” and having an upper end constrained tothe handling mechanism 38 and a lower end defining the gripping area 33.According to a possible embodiment of which the accompanying examplesare a non-limiting example, the handling mechanism 38 comprises a camdisc 40 handled in rotation around the gripping axis “Z” by the drivingactuator 37 and a plurality of rollers 41, each associated with asupport 39. Supports 39 are radially movable along a spoke 42 of aradial element 43. An elastic return device 44 is interposed betweeneach support 39 and the radial element 43. As a result of an actuationof the driving actuator 37, the cam disc 40 rotates according to arrow“R” in FIG. 13 and causes the radial centrifugal displacement ofsupports 39 in contrast to the elastic return device 44. The rotation inthe opposite direction of the cam disc 40 allows the centripetal radialdisplacement of supports 39 by the effect of the elastic return device44.

According to a possible alternative, not shown, a plurality of actuatorsis configured for autonomously adjusting the radial position of eachgripping element 35 or groups of gripping elements.

According to a possible embodiment, the gripping elements 35 may bearranged in groups and each group is associated with a driving actuatorconfigured for adjusting the radial position thereof in a simultaneousand synchronised manner or autonomously.

Preferably, the gripping elements 35 are configured for exerting apneumatic suction action adapted to generate a predetermined degree ofvacuum between the radially outer surface 2 b of the green tyre and thegripping areas 33. Preferably, each gripping element 35 comprises asuction or spongy interface 45 adapted to come into contact with theradially outer surface of the green tyre 2. Preferably, interface 45 isconnected to a suction device by means of a suction conduit.

According to a possible embodiment, of which the accompanying drawingsare a non-limiting example, interface 45 defines a gripping area 33.

Preferably, a detection device 46 is provided for detecting the degreeof vacuum applied by the gripping elements between the radially outersurface of the green tyre and the gripping areas 33 and for generating adetection signal indicative of the vacuum degree detected. Preferably,the control unit “C” is programmed for receiving the detection signal,comparing it with a threshold value indicative of the actual gripping ofthe green tyre 2 and activating the transfer member 31 if the abovecomparison confirms the actual gripping of the green tyre.

A centring group 47 is configured for aligning the gripping axis “Z”with the geometric axis of rotation “X” of the green tyre arranged inthe profiling unit 11 and thus with the central geometric axis “Y” ofthe profiling member 17.

According to a possible embodiment, the centring unit 47 comprises afirst centring portion associated with the gripping device 30 and asecond centring portion associated with the profiling unit 11. Inparticular, the first and second centring portion define a shapecoupling configured for aligning the gripping axis “Z” with thegeometric axis of rotation “X” of the green tyre arranged in theprofiling unit 11, i.e. with the central geometric axis “Y” of theprofiling member 17.

According to the embodiment shown, the first portion associated with thegripping device 30 is implemented by a tailstock 48 tubular in shape,having an upper end of with truncated-cone shape. The second centringportion associated with the profiling unit 11 is implemented by saidcoupling shank 16.

Preferably, the gripping device 30 comprises a frame 49, for examplecomprising the radial element 43, supporting the gripping sector 32.Frame 49 is movable along the gripping axis “Z” with respect to thefirst centring portion. Preferably, at least one elastic element 50 isinterposed between 49 frame and the first centring portion. According tothe example shown, the elastic element 50 is configured and arranged soas to oppose the approach between frame 49 and the first centringportion and allow the elastic return to a predetermined relativeposition of frame 49 and of the first centring portion.

In use, plant 1 as described above allows implementing a method forhandling a green tyre for bicycle according to the present invention inwhich the profiling unit 11 arranged the profiled green tyre asdescribed above.

The gripping axis “Z” of the gripping device 30 not associated with agreen tyre is aligned with the geometric axis of rotation “X” of thegreen tyre arranged in the profiling unit 11 and thus with the centralgeometric axis “Y” of the centring mandrel 12.

This alignment is designed to coaxially position the gripping device 30around the green tyre. In particular, the transfer member 31 places thegripping device 30 with the gripping elements 35 arranged in the restconfiguration coaxially above the profiling unit 11.

An axial translation, for example descent, of the gripping device 30 isthen determined along the gripping axis “Z”, to obtain the mutualengagement between the coupling shank 16 and tailstock 48 counter-shapedthereto, coaxially borne by the gripping device 30. The engagement oftailstock 48 with the coupling shank 16 defines a shape couplingconfigured to determine a precise alignment of the gripping device 30with the gripping axis “Z” thereof coaxially aligned with respect to thecentral geometric axis “Y” of the profiling member 17 and thus, withrespect to the geometric axis of rotation “X” of the green tyre 2. Therelative movement between frame 49 and tailstock 48 determines thecorrect relative positioning along the geometric axis of rotation “X”corresponding to the axial gripping position. As exemplified in FIG. 9,in the axial gripping position, the gripping areas 33 are placed at theaxial centreline plane “M” of tyre 2 arranged in the profiling unit 11.

Preferably, the lowering towards the axial gripping position is carriedout by maintaining the gripping elements 35 in the rest condition, thusreducing the risk of sliding and/or interference against the green tyre2. Upon reaching the axial gripping position, the above driving actuator37 can be activated, which causes the translation of the grippingelements 35 towards the working configuration, approaching the treadband 6 of tyre 2.

Moreover, it is further preferably provided that the lowering of thegripping device 30 towards the axial gripping position is carried outafter the beginning of the profiling operation of tyre 2, but beforesuch a profiling operation has been completed.

More in particular, such a lowering takes place for example when theprofiling member 17 has been returned to the contracted condition aftercarrying out at least one expansion action.

Upon reaching the working configuration, the gripping elements 35 may bestill slightly distanced with respect to tyre 2. In this case, a lastexpansion action imposed to the profiling member 17 brings the treadband 6 against the gripping elements 32, thus expanding the green tyrefrom the interior up to reaching the expanded configuration.

Alternatively, it may be provided that the radial contraction of thegripping elements 35 takes place when the profiling member 17 and thusthe green tyre has already reached the expanded condition following thelast expansion action. In this case, upon reaching the workingconfiguration, the gripping elements 35 come into contact with tyre 2,against the outer surface of the tread band 6 while the profiling member17 and thus the green tyre is preferably in the expanded condition.

In both cases, by means of the profiling unit 11, it is provided toexert a thrust action on a radially inner surface of the green tyredirected radially outwards for expanding the green tyre from theinterior up to reaching the expanded configuration (FIG. 10).

When the radially outer surface 2 b of the tire and the at least onegripping area 33 are in mutual contact, the pneumatic suction action isactivated.

The pneumatic suction effect produced by interface 45 makes the grippingelements 35 be operatively activated against a radially outer surface ofthe tread band 6, exerting attraction actions “A” directed in radialdistancing of the geometric axis of rotation “X” of tyre 2, anddistributed along the whole circumferential development of the latter(FIG. 10).

The engagement of tyre 2 to the transfer member 31 can thus be obtainedwhile tyre 2 itself is still mechanically retained by the profilingmember 17, which imposes retaining the cross-sectional convex profile ina radially outer direction.

Once the engagement has taken place, the profiling member 17 can bereturned to the radially contracted condition, so that tyre 2 can beaxially removed from the profiling unit 11 by the effect of the liftingof the gripping device 30. In other words, the thrust action whichbrings the green tyre to the expanded configuration is cancelled beforehandling the gripping device 30 (FIG. 11).

The attraction actions exerted on the tread band 6 by the grippingelements 35 mechanically retain tyre 2, thus ensuring the maintenance ofthe latter in the profiled condition even after the disengagementthereof from the profiling member 17. Tyre 2 is therefore adapted toretain a stable geometrical shape for the correct transfer to the nextworking station. In particular, retaining the profiling conditionfavours the correct engagement of tyre 2 with the members designed tothe treatment thereof in the vulcanisation press or other subsequentworking station.

In the case in which, as shown, the gripping sector 32 is arrangedcircumferentially around the gripping axis “Z” and defines an annulargripping portion, in order to pick up the green tyre from the profilingunit 11 it may be advantageously provided to select an annular grippingband “B” of the green tyre arranged around the geometric axis ofrotation “X” at a predetermined height along the geometric axis ofrotation itself.

In this case, in order to adjust the gripping device 30, it may beprovided to adjust the annular gripping portion to the adjustmentdiameter and subsequently bring the annular gripping portion in aradially outer position with respect to the annular gripping band “B”.The annular gripping portion is arranged at the height of the annulargripping band “B”, i.e. in the axial gripping position, for example bymeans of a relative axial translation movement between the annulargripping portion and the annular gripping band “B” to arrange them atthe same height along the geometric axis of rotation “X” of the greentyre (FIG. 9).

The annular gripping band “B” and the relative height are selected as afunction of the tyre width. Preferably, the annular gripping band “B” isan annular axial centreline band of the tyre and belongs to the treadband of the tyre.

Once the height of the annular gripping band “B” has been reached, it isprovided to adjust the annular gripping portion to the grippingdiameter. The gripping diameter coincides with the outer diameter of theannular gripping band “B” optionally in the expanded configuration, soas to activate the annular gripping portion against the annular grippingband.

As described above with reference to the gripping elements 35, theadjustment of the annular gripping portion may be carried out byadjusting simultaneously and synchronously the radial position of allgripping areas or autonomously adjusting the radial position of eachgripping area.

The gripping area is thus activated against the radially outer surface 2b of the annular gripping band “B”. In particular, the annular grippingportion is placed in contact with the annular gripping band “B” toactivate the gripping area against the radially outer surface 2 b of thegreen tyre 2, and in particular to activate the pneumatic suctionaction.

The pneumatic suction effect produced through the annular grippingportion exerts the above attraction actions “A” directed radially awayof the geometric axis of rotation “X” of tyre 2, and distributed alongthe whole circumferential development of the latter.

As already described above, before moving the green tyre away from theprofiling unit 11, it is provided to cancel the thrust action that hasbrought it to the expanded configuration.

Once the tyre has been separated from the profiling unit 11, during thehandling of the gripping device, the green tyre 2 is retained by thegripping device 30 hanging only at the annular gripping band “B”.

Thereafter, with reference for example to FIGS. 16-18, the grippingdevice 30 which carries a second green tyre 2 is centred with respect tothe subsequent working station 100, by aligning the gripping axis “Z”and consequently the geometric axis of rotation “X” with a referenceaxis “K” of the subsequent working station 100 (FIG. 16).

Preferably, it is provided to carry out a relative axial translationmovement between the gripping device 30 and the subsequent workingstation for bringing the axial centreline plane “M” of the green tyre 2at an axial reference 51 arranged at a predetermined height along thereference axis “K” of the subsequent working station 100 (FIG. 17).

Thereafter, it is provided to release the green tyre 2 in the subsequentworking station 100, preferably in a suitable processing position withrespect to the subsequent working station (FIG. 18).

According to a possible embodiment, of which the accompanying drawingsare a non-limiting example, the gripping device 30 is a loader of avulcanisation mould 101.

According to a possible embodiment, the vulcanisation mould 101comprises two half-moulds, of which FIGS. 16-18 show a lower half-mould102, and a central body 103 preferably movable with respect to the lowerhalf-mould 102. The upper half-mould is not shown. The reference axis“K” of the subsequent working station corresponds to the reference axisof the central body 103 along which the central body itself is movablein translation.

The movement of the gripping device 30 then provides to load the greentyre into the vulcanisation mould 101 for example by releasing the greentyre 2 on the central body 103.

After releasing the green tyre 2 to the subsequent working station 100,in particular to the vulcanisation mould 101, the transfer member 31repositions the gripping device 30 at the profiling unit 11 on whichanother tyre to be handled is made available.

1. Method for handling a green tyre (2) for bicycle, comprising:arranging a green tyre (2) for bicycle profiled according to a circularextension around a geometric axis of rotation (X) of the green tyre (2)itself and according to a convex cross-section profile in a radiallyouter direction, said geometric axis of rotation (X) being arranged in apredefined position; arranging a gripping device (30) defining agripping sector (32) distributed around a gripping axis (Z), saidgripping sector (32) comprising at least one gripping area (33) whichcan be activated on the green tyre (2); aligning said gripping axis (Z)with the geometric axis of rotation (X) of the green tyre (2) forcoaxially positioning the gripping device (30) around the green tyre(2); activating said at least one gripping area (33) against a radiallyouter surface (2 b) of the green tyre (2) so as to retain said greentyre (2) thus arranged; handling said gripping device (30) to asubsequent working station (100) of the green tyre (2) while saidgripping device (30) continues to retain the green tyre (2).
 2. Methodfor handling a green tyre (2) for bicycle as claimed in claim 1, whereinsaid gripping sector (32) comprises a plurality of said gripping areas(33) distributed discretely around said gripping axis (Z).
 3. Method forhandling a green tyre (2) for bicycle as claimed in claim 1, whereinsaid gripping sector (32) comprises a single gripping area distributedcontinuously around said gripping axis (Z).
 4. Method for handling agreen tyre (2) for bicycle as claimed in one or more of the precedingclaims, wherein said gripping sector (32) is arranged circumferentiallyaround said gripping axis (Z) and defines an annular gripping portion.5. Method for handling a green tyre (2) for bicycle as claimed in claim4, comprising selecting an annular gripping band (B) of the green tyre(2) arranged around the geometric axis of rotation (X) at apredetermined height along the geometric axis of rotation itself andactivating said at least one gripping area (33) of the annular grippingportion against the radially outer surface (2 b) of the annular grippingband (B).
 6. Method for handling a green tyre (2) for bicycle as claimedin claim 5, wherein said annular gripping band (B) and the relativeheight along the geometric axis of rotation (X) of the green tyre (2)are selected as a function of the tyre width.
 7. Method for handling agreen tyre (2) for bicycle as claimed in claim 5, wherein said annulargripping band (B) is an annular axial centreline band of the tyre. 8.Method for handling a green tyre (2) for bicycle as claimed in claim 5,wherein said annular gripping band (B) belongs to a tread band (6) ofthe tyre.
 9. Method for handling a green tyre (2) for bicycle as claimedin one or more of claims 5 to 8, wherein activating said gripping area(33) against the radially outer surface (2 b) of the green tyre (2)comprises arranging said annular gripping portion in contact with saidannular gripping band (B).
 10. Method for handling a green tyre (2) forbicycle as claimed in one or more of claims 5 to 9, wherein during thehandling of the gripping device (30), the green tyre (2) is retained bythe gripping device (30) hanging only at the annular gripping band (B).11. Method for handling a green tyre (2) for bicycle as claimed in oneor more of the preceding claims, wherein said gripping device (30)comprises a plurality of gripping elements (35) distributed around thegripping axis (Z), each gripping element (35) of said plurality ofgripping elements (35) defining a gripping area (33).
 12. Method forhandling a green tyre (2) for bicycle as claimed in claim 11, comprisingadjusting the gripping elements (35) by radially handling them withrespect to the gripping axis (Z) of the gripping device (30) foractivating or deactivating said gripping areas (33) against the radiallyouter surface (2 b) of the green tyre (2).
 13. Method for handling agreen tyre (2) for bicycle as claimed in claim 11 or 12, whereinactivating said gripping areas (33) against the radially outer surface(2 b) of the green tyre (2) comprises exerting a pneumatic suctionaction through said gripping elements (35) adapted to generate apredetermined degree of vacuum between the radially outer surface (2 b)of the green tyre (2) and the gripping areas (33).
 14. Method forhandling a green tyre (2) for bicycle as claimed in one or more of thepreceding claims, wherein arranging said green tyre (2) comprisesexerting a thrust action on a radially inner surface (2 a) of the greentyre (2) directed radially outwards for expanding said green tyre (2)from the interior up to reaching an expanded configuration.
 15. Methodfor handling a green tyre (2) for bicycle as claimed in claim 14,wherein said at least one gripping area (33) is activated against theradially outer surface (2 b) of the green tyre (2) arranged in theexpanded configuration.
 16. Method for handling a green tyre (2) forbicycle as claimed in claim 14 or 15, comprising cancelling said thrustaction prior to handling said gripping device (30).
 17. Method forhandling a green tyre (2) for bicycle as claimed in one or more of thepreceding claims, wherein activating said at least one gripping area(33) against the radially outer surface (2 b) of the green tyre (2)comprises arranging said at least one gripping area (33) in contact withsaid radially outer surface (2 b) of the green tyre (2).
 18. Method forhandling a green tyre (2) for bicycle as claimed in one or more of thepreceding claims, wherein said gripping area (33) is activated againstthe radially outer surface (2 b) of the green tyre (2) by means of anattraction action (A) acting on the radially outer surface (2 b) of thegreen tyre (2) moving away from the geometric axis of rotation (X). 19.Method for handling a green tyre (2) for bicycle as claimed in claim 18,wherein said attraction action (A) is exerted by means of a pneumaticsuction action adapted to generate a predetermined degree of vacuumbetween the radially outer surface (2 b) of the green tyre (2) and saidat least one gripping area (33).
 20. Method for handling a green tyre(2) for bicycle as claimed in claim 19, comprising, before handling saidgripping device (30), verifying the attainment of a predetermined degreeof vacuum between the radially outer surface (2 b) of the green tyre (2)and said at least one gripping area (33), said predetermined degree ofvacuum being indicative of the actual gripping of the green tyre (2).21. Method for handling a green tyre (2) for bicycle as claimed in oneor more of the preceding claims, wherein said at least one gripping area(33) is activated against a radially outer surface (2 b) of the greentyre (2) comprising an axial centreline plane (M) of the green tyre (2).22. Method for handling a green tyre (2) for bicycle as claimed in oneor more of the preceding claims, wherein said at least one gripping area(33) is activated against a radially outer surface (2 b) of a tread band(6) of the green tyre (2).
 23. Method for handling a green tyre (2) forbicycle as claimed in claim 22, wherein during the handling of thegripping device (30), the green tyre (2) is retained by the grippingdevice (30) hanging only at the radially outer surface (2 b) of thetread band (6).
 24. Method for handling a green tyre (2) for bicycle asclaimed in one or more of the preceding claims, wherein said green tyre(2) is kept with said geometric axis of rotation (X) arrangedtransversely with respect to a horizontal geometric plane (O). 25.Method for handling a green tyre (2) for bicycle as claimed in one ormore of the preceding claims, wherein said gripping device (30) ishandled with said gripping axis (Z) arranged transversely with respectto a horizontal geometric plane (O).
 26. Method for handling a greentyre (2) for bicycle as claimed in one or more of the preceding claims,wherein said green tyre (2) is arranged and positioned in the subsequentworking station (100) defining a reference axis (K) arrangedtransversely with respect to a horizontal geometric plane (O). 27.Method for handling a green tyre (2) for bicycle as claimed in one ormore of the preceding claims, wherein handling said gripping device (30)comprises loading said green tyre (2) in a vulcanisation mould (101).28. Plant (1) for handling a green tyre (2) for bicycle, comprising: aprofiling unit (11) configured for receiving a green tyre (2) forbicycle and for profiling it according to a circular extension around ageometric axis of rotation (X) of the green tyre (2) and according to aconvex cross-section profile in a radially outer direction, arranging itwith said geometric axis of rotation (X) in a predefined position withrespect to the profiling unit; a gripping device (30) defining agripping sector (32) distributed around a gripping axis (Z), saidgripping sector (32) comprising at least one gripping area (33) whichcan be activated on the green tyre (2), wherein said gripping device(30) is configured for retaining said green tyre (2) from the exteriorat a radially outer surface (2 b) against which said at least onegripping area (33) is activated; a transfer member (31) comprising saidgripping device (30) and configured for handling said gripping device(30) towards at least one subsequent working station (100); a centringgroup (47) configured for aligning said gripping axis (Z) with thegeometric axis of rotation (X) of the green tyre (2) arranged in theprofiling unit (11).
 29. Plant (1) for handling a green tyre (2) forbicycle as claimed in claim 28, wherein said gripping sector (32)comprises a single gripping area (33) distributed continuously aroundsaid gripping axis (Z).
 30. Plant (1) for handling a green tyre (2) forbicycle as claimed in claim 28, wherein said gripping sector (32)comprises a plurality of said gripping areas (33) distributed discretelyaround said gripping axis (Z).
 31. Plant (1) for handling a green tyre(2) for bicycle as claimed in claim 30, wherein said gripping device(30) comprises a plurality of gripping elements (35) distributed aroundsaid gripping axis (Z), each gripping element (35) of said plurality ofgripping elements (35) defining a gripping area (33).
 32. Plant (1) forhandling a green tyre (2) for bicycle as claimed in claim 31, whereinsaid gripping elements (35) are distributed circumferentially so thatsaid gripping areas (33) define an annular gripping portion.
 33. Plant(1) for handling a green tyre (2) for bicycle as claimed in claim 31 or32, wherein said gripping elements (35) are arranged in groups andwherein each group is associated with a driving actuator (37) configuredfor adjusting the radial position thereof.
 34. Plant (1) for handling agreen tyre (2) for bicycle as claimed in one or more of claims 31 to 33,wherein said gripping elements (35) are configured for exerting apneumatic suction action adapted to generate a predetermined degree ofvacuum between the radially outer surface (2 b) of the green tyre (2)and the gripping areas (33).
 35. Plant (1) for handling a green tyre (2)for bicycle as claimed in claim 34, comprising a detection device (46)configured for: detecting the degree of vacuum between the radiallyouter surface (2 b) of the green tyre (2) and said gripping areas (33)applied by the gripping elements (35), and generating a detection signalindicative of the detected degree of vacuum.
 36. Plant (1) for handlinga green tyre (2) for bicycle as claimed in claim 35, comprising acontrol unit (C) programmed for: receiving said detection signal andcomparing it with a threshold value indicative of the actual grip of thegreen tyre (2), activating said transfer member (31) if said comparisonconfirms the actual gripping of the green tyre (2).
 37. Plant (1) forhandling a green tyre (2) for bicycle as claimed in one or more ofclaims 28 to 36, wherein said centring group (47) comprises a firstcentring portion associated with the gripping device (30) and a secondcentring portion associated with the profiling unit (11), said first andsecond centring portions defining a shape coupling configured foraligning said gripping axis (Z) with the geometric axis of rotation (X)of the green tyre (2) arranged in the profiling unit (11).
 38. Plant (1)for handling a green tyre (2) for bicycle as claimed in claim 37,wherein said gripping device (30) comprises a frame (49) which supportssaid gripping sector (32), said frame (49) being movable along thegripping axis (Z) with respect to the first centring portion.
 39. Plant(1) for handling a green tyre (2) for bicycle as claimed in one or moreof claims 28 to 38, wherein said gripping device (30) is configured forretaining said green tyre (2) hanging with said geometric axis ofrotation (X) and said gripping axis (Z) arranged transversely withrespect to a horizontal geometric plane (O).
 40. Plant (1) for handlinga green tyre (2) for bicycle as claimed in one or more of claims 28 to39, configured for keeping said geometric axis of rotation (X) of thegreen tyre (2) arranged transversely with respect to a horizontalgeometric plane (O).
 41. Plant (1) for handling a green tyre (2) forbicycle as claimed in one or more of claims 28 to 40, wherein anadjustment apparatus (36) is provided, configured for arranging said atleast one gripping area (33) in predetermined radial positions withrespect to the geometric axis of rotation (X) of the green tyre (2).